Spring binding post



Nov; 13, 1956 F, G, BOLTE 2,770,789

SPRING BINDING POST Filed Jan. 12, 1953 FIG. I.

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INVENTOR. F 6: B04 72' United States Patent 2,770,739 SPRING BINDING POST Frederick G. Bolte, Nutley, N. J., assignor to International Telephone and Telegraph Corporation, a corporation of Delaware Y Application January 12, 1953, Serial No. 330,719 7 2 Claims. I (Cl. 339-455) post is the spring type in which the electrical connection is made by a wedging action bctweenthe conductor and certain parts of the binding post. This type of binding post, for certain applications, has many advantages over the type requiring solder; perhaps the most significant advantage is its simplicity. Although many types of spring binding posts are known, none of these achieve the desired simplicity and ruggedness required for all conditions. Simplicity in design is desired because, first, it generally reduces the cost of manufacturing the binding post and, secondly, it makes easier the operation of the binding post. Ruggedness in-design is desired for increased durability, even under the most adverse of conditions. For example, a desirable binding post is one that could be satisfactorily used while exposed to the rigors of winter climate, by an operator wearing gloves, and yet a binding post that is cheap to manufacture.

Accordingly, it is the object of this invention to provide a spring binding post which is simple to manufacture comprising very few parts, and which is easy to operate. In accordance with an aspect of this invention, there is provided an electrical binding post for coupling a conductor to a circuit, comprising a body member in the shape of an incomplete cylinder and a housing surrounding the cylinder, the housing and cylinder defining a tapered space therebetween. A lock-cam member is provided either integral with, or coupled to the housing. The cam member is slidable in the space and has a taper opposite and corresponding to the taper of the space. Also, it is dimensioned to contact the discontinuous surface of the cylinder when positioned toward one end thereof, and is spaced from this surface when displaced toward the other end. Resilient means, such as a spring, is positioned between the body member and the housing tending to urge the members apart longitudinally the extent of longitudinal movement being limited by the cam member contacting the discontinuous surface of the cylinder at said one end. An opening is provided in the housing which is aligned with the space between the member and the cylinder formed when the spring is compressed to receive the conductor. Upon releasing the spring, the cam member wedges said conductor rigidly against the cylinder thereby producing good electrical contact between the cylinder, cam member and conductor. The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood, by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. 1 illustrates a front view partly in section of an embodiment of the electrical binding post; and

Patented Nov. 13, 1956 Fig. 2 illustrates a top view of the embodiment shown in Fig. 1.

Referring now to the drawing there is shown a spring type electrical binding post, for coupling a conductor (not shown) to a circuit. The post-comprises a body member 1 in the shape of an incomplete cylinder, and a housing 2 surrounding the cylinder 1 and defining a tapered space 3 therebetween; the space extending longitudinally with respect to the axis of the cylinder. The space 3 may be formed by a cam slot made in the cylinder 1 or the cylinder may be truncated along its longitudinal surface. The slot preferably, although not necessarily, hasa uniformly inclined surface 4 from one end 5 of the cylinder towards the other end 6. A lock cam member 7, which may be cast or otherwise formed integrally with the housing 2, or, as shown, may be a separate member, has a corrugated surface 8, preferably parallel to the inclined surface 4. Of course,v the corrugations may be formed on the surface 4, or on both the surface 4 and cam member 7. The cam member 7 I is slidable in the space 3, and is dimensioned to contact the inclined surface when positioned toward the end 5 of the cylinder, and to be spaced from the inclined surface 4 when moved toward the end 6. The cam member 7 is fixedly connected to the housing 2, by having formed thereon an undercut projection 8a fitting into an aperture 9 in the housing 2. Grooves 10 are provided in the.

housing immediately above and below the aperture 9 so that in assembling the unit, the cam member may be permanently secured by crimping the material 11 against the projection 8a. Of course, if the housing is not made of a deformable material, other suitable methods may be used to fix the cam member to the housing. Resilient means, preferably a coil spring 12 is secured between the cylinder 1 and the housing 2 by means of a lug 13 and a well 14, formed in the cylinder and housing respectively. The action of the spring tends to normally separate the members longitudinally the extent of separation being limited by the cam member 7 contacting the inclined surface 4 at the end 5 of the cylinder. The housing 2 is provided with an opening 15 in the end cap of the cylinder 1 and aligned with the space formed between the cam member and the cylinder when the spring is compressed. A conductor is inserted into this space and upon releasing the spring, the cam member pushes the conductor rigidly against the inclined surface. The corrugations bite into the surface of the conductor producing good electrical contact between the cylinder 1, lock cam and conductor.

Under certain conditions, for example, under war combat conditions where operation in darkness may be necessary, it is helpful to coat the sides of the opening with a luminescent paint.

As shown, the terminal post may include another portion 16 for connection to a panel or insulator board, whereby a second conductor may be electrically connected to the first. The second portion comprises a threaded stud 17 for threadedly engaging the panel; the stud 17 being provided with an opening 18 in which the second conductor may be affixed. A collar 19 is provided on the stud 17. Formed in the collar 19 is a channel 20 into which a water proofing seal may be applied. Between the collar 19 and the body portion 1, there is provided a lateral opening 21 joining the space 3, whereby broken bits of wire may be easily removed.

On top of the housing 2 (Fig. 2) lateral grooves 22 are provided for engagement with a tool, such as a screw driver, for displacing the housing when other ways of gripping are inconvenient.

It is to be realized, of course, that the various parts of the post may be made from any suitable material which does not render the device inoperative. For example, the housing may be made of a plastic, such as nylon, or metal.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of my inventionas set forth in the objects thereof and in the accompanying claims.

What is claimed is:

1. An electrical binding post for engaging a conductor, comprising a body member having an elongated slot, the slot extending linearly along one surface of the body member and the depth of the slot gradually increasing from one end of the body member towards the other end thereof defining an inclined surface, a hollow housing member closed at one end and surrounding said body member, said closed end having an opening whereby a conductor may be inserted therethrough, a cam element slidable in said slot and having a corrugated inclined surface substantially parallel to and adjacent the inclined surface of said'slot, means attaching said cam element relatively immovably to said housing member, whereby the cam element and housing member are movable together in a common direction relative to said body member, spring means positioned between said closed end of said housing and said body member and tending to move the body member in one direction and the housing member in the opposite direction, the position of said members being such that the movement therebetween is limited at one extreme position by said inclined surfaces contacting each other, and at the other extreme position of movement, opposing the normal action of said spring, said inclined surfaces are separated a maximum distance, the portion of the space near said closed end being aligned with the opening in said housing member, whereby a conductor may be inserted into the space between said surfaces and wedged therebetween by the action of said spring upon release.

2. A binding post according to claim 1, wherein said means attaching said cam element to said housing mem ber comprises an aperture in said housing member, and a projection on said cam element fitting .into said aperture to hold said cam element detachably in place by the interfitting of said projection and aperture, the parallel faces of said cam and slot and the pressure of said spring.

References Cited in the file of this patent UNITED STATESPATENTS 2,287,035 Hubbell June 23, 1942 2,395,326 Handley Feb. 19, 1946 2,677,745 Leon May 4, 1954 FOREIGN PATENTS 379,753 Great Britain Sept. 5, 1932 721,999 Germany June 26, 1942 

